Effect of Furrow Method and Mulch on Bulb Yield and Water Productivity of Irrigated Onion under Central Highland Vertisol of Ethiopia

The aim of this study was to select the most effective water-saving techniques and improve the water use efficiency of irrigated onions under limited agricultural water availability. The experiment was conducted in split plot design with three types of furrow irrigation methods and mulch types in three replications. The result revealed that different types of furrow method and mulch type are significantly affected (p<0.01) marketable yield of onion. It has been observed that the significantly highest marketable yield (39.5 t/ha) of onion was recorded due to CFI and followed by AFI method (34.3 t/ha). However, the highest WUE (9.7 kg/m3) was obtained due to AFI method when compared with the CFI method of 5.7 kg/m3. Hence, there was 18 to 22% increment of marketable yield and WUE of the onion by applying mulching over the non-mulching condition and also 42% improvement of WUE by using AFI over the conventional furrow method. Therefore, for maximizing the marketable yield of onion under limiting irrigation water resource, irrigation of onion could be done with AFI method with plastic mulch application to minimize evaporation loss and maximize water productivity of onion for similar agro-ecology and soil type.